TAGGED: cfx, heat-transfer
May 17, 2022 at 10:21 amgzhang24Subscriber
I am working on thermal management of electrical machines. I need to use material with different thermal conductivity in different direction to represent the machine winding and somehow we find a way to define an anisotropic material using following code in command editor of material.
Option = Orthotropic Cartesian Components
Thermal Conductivity X Component = 0.87 [W m^-1 K^-1]
Thermal Conductivity Y Component = 0.87 [W m^-1 K^-1]
Thermal Conductivity Z Component = 265.0 [W m^-1 K^-1]
The defined material works fine in single region. However, when two regions are set to be anisotropic material and they are using differnt coordinates, the interface of these two regions seems blocking heat transfer. The second picture is when I put a heat source point in the roughly middle of end winding and the heat cannot transfer to other regions.
I have tried changing factors in intersection settinng of mesh connection but it does not work out.
I wonder what can I do to make it works. Thanks.May 29, 2022 at 8:43 pmrfblumenAnsys EmployeeIf I understand correctly from your explanation of the set up, you have two solid domains, one embedded inside the other. Both solid domains use the same material that has orthotropic thermal conductivity. A point energy source is located in the inner solid. One of the domains uses a local coordinate system that has coordinate directions different from the global coordinate system. You're seeing a discontinuity in temperature at the interface between the two solids.
I set up an example case based on the above, however I wasn't able to see any temperature discontinuity at the interface. I then modified the example such that both solids used the global coordinate system, but had each solid use a different material. The material properties of the two materials were the same except of the direction values of the thermal conductivity. I then saw what appeared to be a "discontinuity" in temperature across the interface due to the difference in thermal conductivity across the interface. However, if the mesh at the interface is refined with appropriate inflation on both sides, the temperature is actually continuous across the interface but has a high gradient proximal to the interface.
You might try the same approach with your case and add mesh inflation to the two sides of the interface.
May 30, 2022 at 8:35 amgzhang24SubscriberThanks fot answering my question and your understanding is totally correct.
I just tried building up a easier model with only the solid winding but no fluid in CFX. However, I am having a more serious problem that the residual became so high. I think I must made some stupid mistakes but I couldn't find out.
Although this model must be wrong, it still shows the same discontinuity in temperature issue.
What confuses me most is that the interface of domin 1 and domin 2 looks fine with a discontnuous probably due to high residual, but the interface of domin 2 and 3 shows a very strange temperature distribution. The 3 domins are using same material that has orthotropic thermal conductivity, but they are using differnet coordinates.
Please give me some suggestions. Many thanks.
Viewing 2 reply threads
Ansys Innovation Space
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.Trending discussions
- Suppress Fluent to open with GUI while performing in journal file
- Floating point exception in Fluent
- What are the differences between CFX and Fluent?
- Heat transfer coefficient
- Getting graph and tabular data from result in workbench mechanical
- The solver failed with a non-zero exit code of : 2
- Difference between K-epsilon and K-omega Turbulence Model
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error in cfd post
Top Rated Tags
© 2023 Copyright ANSYS, Inc. All rights reserved.Ansys does not support the usage of unauthorized Ansys software. Please visit www.ansys.com to obtain an official distribution.